Here are a few good tips!

1. The tires: Some tires lose air very slowly and a soft tire, although it might not be obvious, is a major safety issue. On a motorcycle, you have half the number of tires you do on a car making proper inflation twice as important.
2. The fluid: It's always good to check the various fluids, including the engine oil, transmission oil, and brake fluid, etc. after an idle spell. They're easier to check after the bike's been sitting for a while and the fluids have settled to their lowest point.
3. The air filters: Make sure they're clean, and check for small creatures (they can be crafty) in the housing. If you find that you need to replace a filter, it may not be as difficult as you think.
4. The battery: It's not unusual for the battery to be low or even dead after sitting for an extended period. Check the water in the battery and make sure there's enough charge left to start the bike.
5. The lights: Make sure they're all working. Sounds obvious, sure, but that means it's also easy to forget.

And of course, a big part of staying safe is making sure you have reliable motorcycle insurance.